Tuesday, May 29, 2007

Werewolf Syndrome aka Congenital Generalized Hypertrichosis

In earlier eras, people afflicted with CGH would stay indoors during the day, going out only at night, to avoid being ostracized. Because of this behavior, people began to associate these unfortunate folks with werewolves, thus the vulgar name of Werewolf Syndrome. CGH is characterized, in its severest form, by thick hair covering the entire body, sparing the palms of the hands, and soles of the feet! Researchers believe the cause to be a genetic mutation, or an “awakening” of a very old, dormant gene-harkening back in evolution to hairier times!

CGH is extremely rare, with only about 50 documented cases since the Middle Ages. One of the first documented cases was found in French King Henry II’s court! King Henry was highly interested in human oddities and quirks of nature, and in 1547 was given, as a gift, a 10 year old boy who appeared to be half human, half animal. Four inch, thick blond fur covered his entire body, except for lips and eyes. The boy’s name was Pedro Gonzales, born in the Canary Islands. Pedro married a lovely French woman, and fathered many children, five of which inherited their father's genetic defect. Many portraits were painted of this unusual family-some still hang in theAmbrasCastle, near Innsbruck, Austria. Since then, known cases have appeared in China, Poland, Germany, Russia, and Mexico.

Researchers are familiar with other atavistic genetic behavior. Some rare examples include additional nipples, and small tail-like extrusions at the end of the spine. The defective gene in CGH is passed by both sexes, to 50% of their offspring. Typically, fetuses lose their fine body hair, called lanugo, by the end of the seventh and eight month of gestation. Babies afflicted with CGH are born with this body hair intact, which occasionally fades in adulthood, but typically lastis a lifetime.

Currently, the best known cases of CGH occurs in a family living in Mexico. Sadly, much of this family has resorted to working in circuses and “freak” shows to earn a living. This Mexican family grows an even thicker, darker body hair than their Asian, and European counterparts. Men have thicker and denser hair than the women in this family, suggesting an X-linked dominant pattern of inheritance.

“"This is probably a mutation of a gene that was a sleeping beauty," said Dr. Jose M. Cantu, head of genetics at the Mexican Institute for Social Security in Guadalajara, an author of the new report. "The mutation awakened a gene that had been put aside during evolution."

But Dr. Cantu and his colleagues emphasized that the idea of generalized hypertrichosis as an atavistic mutation was only a theory. "At this point it's strictly speculation, though the idea is a very interesting one," said Dr. Pragna I. Patel of the HumanGenomeCenter at Baylor College of Medicine in Houston, another author of the report, which appears in the June issue of Nature Genetics.

Biologists have observed many other mutations that they suggest fall into this class of atavisms, the reappearance of normally dormant traits. Some people are born with multiple sets of nipples, for example, just as most nonprimate mammals have a double ridge of mammary tissue down the length of the underside of the torso. In very rare cases, girls develop entire extra breasts at puberty.

Other examples of atavistic mutations include the extension of the human coccyx into a small tail, the appearance of hind limbs in whales and the growth of extra toes on horses and cats.

"Atavistic mutations tell us that a lot of information is kept around for a very long time," said Dr. Brian K. Hall, a developmental biologist at DalhousieUniversity in Halifax, Nova Scotia. "Just because an animal isn't using a gene anymore doesn't mean the information just disappears." Dr. Hall wrote a commentary about atavistic mutations that appears with the report on hypertrichosis.”